Should I use life or lives in the following question

Question

Should I use life or lives in the following question?

I would promote prayer as a part of the pupils' everyday life

I would promote prayer as a part of the pupils' everyday lives

Answer 1

It's "I would promote prayer as a part of the pupils' everyday lives," because it is the group of pupils as a whole who possesses the lives, and it's indeed plural, not one life, so it's "lives".

For contrast, if it were "pupil's", it would be "life" as in, "I would promote prayer as a part of each pupil's everyday life".